1. Field of the Invention
The invention relates to a method and apparatus for changing a region code of a digital versatile disc (DVD) drive.
2. Description of the Prior Art
In modern society, there has been a spread in the use of optical storage medium, such as compact discs, as optical storage media for recording a huge amount of high-density digital information. The optical storage medium has advantages of lightweight, low-price, and large capacity for data storage. As the result of recent research and development, digital versatile disc (DVD) is developed. The development of DVD has brought a dramatic increase in storage capacity, especially suitable for video and audio data. Such DVD has a storage capacity of 4.7 GB (gigabytes), so that video with superior image quality to video compact discs (VCD) can be stored, and the maximum reproduction time can be increased to allow the recording of long titles. For these reasons, DVD allows the storage of movies with long reproduction time and high picture quality, making DVD more suitable for AV (audio-video) application and data storage.
In order to protect the copyrights of video data on DVD, DVD is stipulated to include a particular region code. Meanwhile, digital versatile disc drives used for reading data on DVD also include a particular region code. Before a DVD drive can read video data on a DVD, the DVD drive first has to check whether region code of the DVD and the DVD drive are identical. If the region code of the DVD is not the same as the region code of the DVD drive, the DVD drive cannot read the data on the DVD. Conversely, when the two region codes are identical, the DVD drive can read data accurately.
The establishment of the above-mentioned region code system was made to protect the copyrights of video data on DVD. Nevertheless, the reasonable right of users to read video data on DVD needs to be taken into consideration. Therefore, a DVD drive is designed to be capable of changing its region code within fixed times, such as six times typically. For providing the above-mentioned function, a DVD drive stores a value in a counter for recording the number of times the region code of the DVD drive has been changed. When a region code of a DVD is not the same as the region code of the DVD drive, the DVD drive then checks the value stored in the counter to determine whether the value of the counter is smaller than the default value. If the value in the counter is smaller than the fixed value, the DVD drive is allowed to change its region code so as to read video data on DVD. The DVD drive then sends a message to ask a user whether or not to change the region code of the DVD drive. If the user does not want to change the region code of the DVD drive, the DVD drive cannot read video data on DVD. On the other hand, when the user requests that the DVD drive to change the region code, the DVD drive changes the region code stored in the DVD drive the same as the region code of DVD. Meanwhile, the value in the counter is incremented by one to represent the number of times that the region code of the DVD drive has been changed. That is, each time the user changes the region code of the DVD drive, the value in the counter is required to be incremented by one. However, when the value in the counter exceeds the fixed value; and the two region codes of the DVD and the DVD drive are not identical, the DVD drive sends a warning message to inform the user that video data on DVD cannot be read. Thereafter, the region code of the DVD drive is not allowed to change any more.
Furthermore, in order to complete the above-mentioned procedure, the prior DVD drive has an electrically erasable programmable read only memory (EEPROM) for storing both the value in the counter and the region code. Please refer to FIG. 1. FIG. 1 is a functional block diagram of a prior DVD drive 10. The DVD drive 10 comprises a controller 12 electrically connected to a volatile memory module 18, a non-volatile memory 14 that stores a source code 14A, and an EEPROM 16. The controller 12 is used to control operations of the DVD drive 10 according to the source code 14A stored in the non-volatile memory 14. The volatile memory module 18 is used to store data temporarily required by the controller 12. The EEPROM 16 is used to store a region code 16A and a value in a counter 16B of the DVD drive 10.
When the prior DVD drive 10 receives a command for changing the region code 16A of the DVD drive 10 and the value in the counter 16B does not exceed a default value, the DVD drive 10 changes the region code 16A according to a default change procedure. Please refer to FIG. 2. FIG. 2 is a flow chart illustrating a method for the prior DVD drive 10 to change the region code 16A. The prior method comprises the following steps:
Step 102
The procedure is started for changing the region code 16A of the DVD drive 10.
Step 104
The controller 12 reads the source code 14A stored in the non-volatile memory 14 and executes the subsequent procedure of changing the region code 16A of the DVD drive 10 according to the source code 14A.
Step 106
The controller 12 erases the region code 16A and the value in the counter 16B that were originally stored in the EEPROM 16.
Step 108
The controller 12 changes the region code 16A according to the indication from a user and increments the value in the counter 16B, and then the controller 12 writes the changed region code 16A and the new value in the counter 16B into the EEPROM 16.
Step 110
The procedure of changing the region code 16A of the DVD drive 10 is completed.
Since the non-volatile memory 14 such as a flash memory is incapable of reading and writing data simultaneously and the controller 12 of the prior DVD drive 10 always has to read the source code 14A through the non-volatile memory 14, the prior DVD drive 10 has to use the EEPROM 16 to store the region code 16A and the value in the counter 16B. Therefore, the cost of the prior DVD drive 10 is substantially increased. Moreover, an additional circuit suitable for the EEPROM 16 is required in the prior DVD drive 10 for, and the design and the fabrication of the prior DVD drive 10 is more complicated.
It is therefore a primary objective of the claimed invention to provide a method and apparatus for changing a region code of a digital versatile disc drive to solve the above-mentioned problem.
According to the claimed invention, a method for changing a region code of a digital versatile disc drive is disclosed. The digital versatile disc drive has a first memory for storing the region code and a source code, and a second memory for storing data temporarily. The method comprises storing the source code in the second memory, and changing the region code in the first memory according to the source code stored in the second memory.
It is an advantage of the claimed invention that the method and apparatus is capable of changing the region code of the digital versatile disc drive so as to overcome shortcomings in the prior art.
These and other objectives of the present invention will no doubt become obvious to those of ordinary skill in the art after reading the following detailed description of the preferred embodiment that is illustrated in the various figures and drawings.